Nevada’s first case of the Omicron variant has been discovered in Clark County, Southern Nevada Health District officials reported Tuesday afternoon.

The case was identified in a fully vaccinated woman in her mid-20s who had not received a booster dose of the vaccine. Health district officials said the specimen was tested by the Southern Nevada Public Health Laboratory, which is sequencing positive cases in the community to detect additional cases of the variant.

“We knew that it was only a matter of time that we would identify the Omicron variant in Southern Nevada,” Dr. Fermin Leguen, the district’s health officer, said in a statement.

Omicron variant cases have now been identified in more than half of states, with California reporting the first Omicron case in the nation on Dec. 1.

Health district officials noted that the Delta variant, which hit Nevada first this summer, remains the dominant variant circulating in Clark County and the United States. The latest variant report from the Nevada State Public Health Lab, dated Nov. 23, showed that the Delta variant was responsible for 100 percent of sequenced cases in the state.

To combat both the Omicron and Delta variants, state and local health officials are urging people to get fully vaccinated — meaning two doses of either the Pfizer or Moderna vaccines or one dose of the Johnson and Johnson vaccine — and receive their booster shot when they become eligible, wear a mask in public indoor settings and stay home and get tested if they are sick.

Scientists are still working to learn more about the Omicron variant, which was classified as a variant of concern by the World Health Organization on Nov. 26. So far, some early evidence has suggested the variant may be more resistant to the vaccine but may cause less severe cases of COVID.

Pfizer-BioNTech last week announced that while the initial two-dose course of the vaccine may not prevent infection by the Omicron variant, the booster shot appears to provide strong protection.

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